i bought a s100 everything works good. i ran it for about a hour and it sounds like front left tire is clicking grinding real loud. but only sometimes and never going in reverse. i jacked it up spun tires and no noise drove its 6 blocks or so no noise so then drove another 3 blocks started moving some snow and it started again so i stopped spin a few circles to left no noise . then i can go forward a while without it doing it sometimes a blocks sometimes 50ft... axles/chains/sprockets all seem good ... i did pull the traction lock/parking brake out and the mechanism is gone. im unsure if someone took it out or what